Unless otherwise indicated herein, the materials described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Purified hydrogen has become a common fuel source. Fuel cells, for example, use purified hydrogen and an oxidant to produce an electrical potential. High purity hydrogen is also used extensively in industrial processing, including hydrogenation of oils and the production of ammonia. To produce purified hydrogen, a reformer and a hydrogen purifier are commonly used. In a typical arrangement, the reformer chemically converts a feedstock over a catalyst to generate impure hydrogen, and the hydrogen purifier extracts pure hydrogen from the reformate using a hydrogen-selective membrane. However, reformers are not the only sources of impure hydrogen. Ammonia crackers and electrolysis systems also produce hydrogen that requires purification prior to use in high-purity applications. Several industrial processes also produce hydrogen, which has the potential to be purified and utilized. For example, chlor-alkali processing plants produce large amounts of hydrogen in their waste gas streams. By using purification, this waste stream can become a commodity, adding value to the chemical plant.